Neurons are not alone in the brain. They are surrounded by a large number of glial cells which have crucial roles in shaping and maintaining structure and function of the central nervous system (CNS). Oligodendrocytes and their committed precursors represent an abundant population of CNS glia with established roles in axonal myelination. However, there are many more oligodendrocyte precursor cells (OPCs) distributed across the CNS lifelong than ever give rise to myelinating oligodendrocytes. My group investigates the mechanisms that govern oligodendrocyte differentiation in the healthy and damaged CNS, and how tissue-resident OPCs affect the CNS when they don’t make myelin. We do this using zebrafish as model organism, which allows us that carry out high-resolution imaging of intercellular interactions, along with genetic and physiological manipulations and analyses.